J Chron Dis 1975, Vol. 28, pp. 125-134. Pergamon Press. Printed in Great Britain
Editorial
TO TREAT OR NOT TO TREAT (Received3 June 1974) HYPERTENSION is a chronic disease whose importance in the United States is finally being accorded widespread public as well as medical recognition. Evidence for this is to be found in the increasing number of articles that deal with elevated blood pressure as a potent mortality or morbidity risk factor. Additional evidence is implicit in the readiness with which medical and lay organizations have voluntarily joined with the Federal Government in a massive detection and control effort, the National High Blood Pressure Education Program [I, 21. This change in attitude toward hypertension can be attributed to at least three different factors: increased awareness of the prevalence of hypertension; confirmation of the extent to which hypertensives are at increased risk for myocardial infarction, stroke, or other cardiovascular complications as well as premature death (there are many recent published reports from the Framingham Heart Study and similar longitudinal studies); and the finding that anti-hypertensive drugs, which have been demonstrated to be effective in controlling morbidity and excess mortality in moderate as well as severe hypertension, are being used in only a relatively small fraction of persons with definite hypertension. The evidence for this is very well summarized by Stamler in a comprehensive review presented at the January, 1973 conference of the National High Blood Pressure Education Program [l]. In this editorial we will consider just one aspect, but a crucial aspect, of the excess mortality associated with hypertension. We propose to estimate the number of excess deaths in a segment of the United States population that can be attributed to hypertension. Available prevalence and mortality data for hypertensives, which will be described, are utilized in conjunction with the latest available U.S. population and mortality figures: the estimated distribution for total U.S. population by age and sex in 1972, and mortality rates from U.S. Life Tables for 1959-1961. The age range for 35-64 yr has been chosen because the most reliable mortality data for hypertensives are in this approximate range. Excess mortality has been calculated over a period of 10 yr, because hypertension is a chronic disease for which a span of 10 yr is a reasonable one over which to forecast excess mortality or morbidity. We believe that the magnitude of excess mortality calculated in this way will constitute one very important eiement that must be considered by the public health expert in deciding how to control hypertension as a chronic disease, and by the physician in deciding when to treat the patient who has this chronic disease. B
125
126
RICHARD B. SINGER
Hypertension is here defined exclusively in terms of the blood pressure criteria proposed by the New York Heart Association, which have been widely accepted and have been adopted by the World Health Organization. Any blood pressure combination up to and including 139/89 is regarded as normotensive. Any systolic pressure 160 and up, or a diastolic pressure 95 and up, is classified as definitely hypertensive. Any combination below 160/95 is regarded as borderline hypertensive, provided that it does not fall within the normotensive range. These definitions are quite arbitrary, but they do offer a convenient, widely used and practical method of classification. Their arbitrary character is evident in life insurance experience, which demonstrates in groups of policyholders of the same age and sex, a continuous increase in mortality associated with increasing levels of systolic or diastolic pressure from the lower part of the range of normal blood pressure, that is, from a blood pressure of the order of 110/75. Casual blood pressure readings are assumed, rather than those taken under basal or other strictly defined conditions. It is also assumed that multiple readings are available, from which an average can be calculated as a basis for the classification. However, in large groups of individuals a single casual reading gives almost the same prevalence figures for hypertension as a distribution based on a series of average blood pressures. TAULE 1. PREVALENCEOF HYPERTENSION IN TAE TOTAL U.S. POPULATION(NATIONAL HEAL.I.HSURVEY 1960-1962)
Age Years
18-24 25-34 35-44 45-54 55-64 65-74 75-79
x
‘,
Editorial
TO TREAT OR NOT TO TREAT (Received3 June 1974) HYPERTENSION is a chronic disease whose importance in the United States is finally being accorded widespread public as well as medical recognition. Evidence for this is to be found in the increasing number of articles that deal with elevated blood pressure as a potent mortality or morbidity risk factor. Additional evidence is implicit in the readiness with which medical and lay organizations have voluntarily joined with the Federal Government in a massive detection and control effort, the National High Blood Pressure Education Program [I, 21. This change in attitude toward hypertension can be attributed to at least three different factors: increased awareness of the prevalence of hypertension; confirmation of the extent to which hypertensives are at increased risk for myocardial infarction, stroke, or other cardiovascular complications as well as premature death (there are many recent published reports from the Framingham Heart Study and similar longitudinal studies); and the finding that anti-hypertensive drugs, which have been demonstrated to be effective in controlling morbidity and excess mortality in moderate as well as severe hypertension, are being used in only a relatively small fraction of persons with definite hypertension. The evidence for this is very well summarized by Stamler in a comprehensive review presented at the January, 1973 conference of the National High Blood Pressure Education Program [l]. In this editorial we will consider just one aspect, but a crucial aspect, of the excess mortality associated with hypertension. We propose to estimate the number of excess deaths in a segment of the United States population that can be attributed to hypertension. Available prevalence and mortality data for hypertensives, which will be described, are utilized in conjunction with the latest available U.S. population and mortality figures: the estimated distribution for total U.S. population by age and sex in 1972, and mortality rates from U.S. Life Tables for 1959-1961. The age range for 35-64 yr has been chosen because the most reliable mortality data for hypertensives are in this approximate range. Excess mortality has been calculated over a period of 10 yr, because hypertension is a chronic disease for which a span of 10 yr is a reasonable one over which to forecast excess mortality or morbidity. We believe that the magnitude of excess mortality calculated in this way will constitute one very important eiement that must be considered by the public health expert in deciding how to control hypertension as a chronic disease, and by the physician in deciding when to treat the patient who has this chronic disease. B
125
126
RICHARD B. SINGER
Hypertension is here defined exclusively in terms of the blood pressure criteria proposed by the New York Heart Association, which have been widely accepted and have been adopted by the World Health Organization. Any blood pressure combination up to and including 139/89 is regarded as normotensive. Any systolic pressure 160 and up, or a diastolic pressure 95 and up, is classified as definitely hypertensive. Any combination below 160/95 is regarded as borderline hypertensive, provided that it does not fall within the normotensive range. These definitions are quite arbitrary, but they do offer a convenient, widely used and practical method of classification. Their arbitrary character is evident in life insurance experience, which demonstrates in groups of policyholders of the same age and sex, a continuous increase in mortality associated with increasing levels of systolic or diastolic pressure from the lower part of the range of normal blood pressure, that is, from a blood pressure of the order of 110/75. Casual blood pressure readings are assumed, rather than those taken under basal or other strictly defined conditions. It is also assumed that multiple readings are available, from which an average can be calculated as a basis for the classification. However, in large groups of individuals a single casual reading gives almost the same prevalence figures for hypertension as a distribution based on a series of average blood pressures. TAULE 1. PREVALENCEOF HYPERTENSION IN TAE TOTAL U.S. POPULATION(NATIONAL HEAL.I.HSURVEY 1960-1962)
Age Years
18-24 25-34 35-44 45-54 55-64 65-74 75-79
x
‘,
